Here's Why Romaine Lettuce Tainted With E.coli O157: H7 Could Be Very Dangerous

The U.S. Centers for Disease Control and Prevention says that chopped romaine lettuce from Yuma, Arizona could be tainted with E. coli O157: H7, which could make people sick.

As of Friday, April 13, 35 people from 11 states have already been infected with the outbreak strain. No death has been reported so far, but of those who fell ill, 22 have been hospitalized including three people who have developed the hemolytic uremic syndrome.

Hemolytic Uremic Syndrome

The hemolytic uremic syndrome occurs as a result of the abnormal destruction of red blood cells. The damaged red blood cells clog the filtering system of the kidney, which can lead to life-threatening kidney failure.

Symptoms include bloody diarrhea, decreased urination or presence of blood in the urine, seizures, fatigue, bleeding from the nose and mouth, pallor, abdominal pain, vomiting, swelling, high blood pressure, and fever.

The HUS from E.coli infections occurs when bacterial toxins from the intestines cross into the bloodstream and damage the small blood vessels.

Dangerous E.Coli Strain

Most strains of E.coli are harmless but O157: H7 is known to cause more severe illness. E. coli O157 causes disease by making a toxin known as Shiga toxin.

"As a whole, the non-O157 serogroups are less likely to cause severe illness than E. coli O157, though sometimes they can," the CDC said.

The strain can cause severe diarrhea that can lead to kidney damage and other serious complications that can be fatal.

A 1996 large E. coli O157 outbreak sickened 70 people who were mostly children. More than one-third of these patients were hospitalized, 20 percent developed HUS, and one died.

A 1999 outbreak linked to contaminated drinking water sickened 781 persons. Of these, 9 percent were hospitalized, 2 percent developed HUS, and two died.

People generally get sick from Shiga toxin-producing E.coli around three to four days after ingesting the germ. Those infected may suffer from bloody diarrhea, severe stomach cramps, and vomiting.

Most people can recover within a week but there is a risk of more severe illnesses in young children below 5 years old, older adults, and those who have a weakened immune system.

Avoid Store-Bought Chopped Romaine Lettuce

"Consumers anywhere in the United States who have store-bought chopped romaine lettuce at home, including salads and salad mixes containing chopped romaine lettuce, should not eat it and should throw it away, even if some of it was eaten and no one has gotten sick," the CDC said.